Liquid crystal display device and method of fabricating the same

Abstract

In applying an alignment material to surfaces of a CF substrate and a TFT substrate, which form a liquid crystal panel, to form alignment films, an alignment film is formed so as to cover at least a display region in which pixels are arranged in a matrix fashion, while a porous alignment film, which has a porous film structure with a higher impurity adsorptive property than the former alignment film, is formed in a region outside the former alignment film, for example, in a region intermediate the display region and a seal region surrounded by a sealing material, whereby the porous alignment film formed in the region outside the display region can efficiently adsorb contaminants, such as residual impurity ions produced from the sealing material and uncured components of the sealing material, to prevent the contaminants from penetrating into the display region and being fixed therein.

1. A liquid crystal display device comprising:
 a pair of substrates; 
 an alignment film formed on each of opposed faces of said pair of substrates; 
 a sealing material formed outside of a display region of at least one of said substrates; and 
 a liquid crystal material encapsulated between said pair of substrates, wherein: 
 said alignment film comprises a first alignment film formed so as to cover at least said display region, and a second alignment film formed in a region lying outwardly of said first alignment film and inwardly of said sealing material; 
 said second alignment film has a higher ionic impurity adsorptive property than said first alignment film; and 
 said second alignment film has a porous film structure. 
 
     
     
       2. The liquid crystal display device according to  claim 1 , wherein said second alignment film has a larger film thickness than said first alignment film. 
     
     
       3. A liquid crystal display device, comprising:
 a pair of substrates; 
 an alignment film formed on each of opposed faces of said pair of substrates; 
 a sealing material formed outside of a display region of at least one of said substrates; and 
 a liquid crystal material encapsulated between said pair of substrates, wherein: 
 said alignment film comprises a first alignment film formed so as to cover at least said display reton. and a second alignment film formed in a region lying outwardly of said first alignment film and inwardly of said sealing material; 
 said second alignment film has a higher ionic impurity adsorptive property than said first alignment film; and 
 a diamine chain forming a main chain contained in said second alignment film is longer than a diamine chain forming a main chain contained in said first alignment film. 
 
     
     
       4. A liquid crystal display device, comprising:
 a pair of substrates; 
 an alignment film formed on each of opposed faces of said pair of substrates; 
 a sealing material formed outside of a display region of at least one of said substrates; and 
 a liquid crystal material encapsulated between said pair of substrates, wherein: 
 said alignment film comprises a first alignment film formed so as to cover at least said display region, and a second alignment film formed in a region lying outwardly of said first alignment film and inwardly of said sealing material; 
 said second alignment film has a higher ionic impurity adsorptive property than said first alignment film; and 
 an imidization rate of said second alignment film is lower than that of said first alignment film.